Exactly how many aircraft defected/fled to Iran from Iraq? Which ones were they? Have they been adopted
by the Islamic Republic of Iran Air Force? Would this raise IRIAF's capability?- question from Sergei Ivanov

I assume you are referring to the Iraqi aircraft that fled to Iran to escape destruction in the early weeks of
the 1991 Gulf War. In that conflict, Iraq kept most of its air force in reserve believing its aircraft would be
safe from attack in underground shelters. Saddam Hussein had used the same tactic during the Iran-Iraq War of
1980 to 1988 believing that the planes should be saved for a critical moment when they would turn the tide.
Hussein had good reason to believe his planes would be safe, for the 594 hardened bunkers they were stored in were
deep underground, reinforced with layers of concrete, and believed to be virtually impenetrable. Perhaps
reinforcing his belief was the fact that coalition forces, led by the United States, focused their initial attacks
on runways and air defense sites rather than the bunkers. This policy changed, however, when US and British strike
aircraft began attacking the hardened shelters with precision laser-guided bombs. Fitted with 2,000 lb (910 kg)
warheads, these weapons were capable of destroying even the most fortified of structures. British
Tornados were used to attack takeoff runways at the
Iraqi airfields while F-111 and
F-117 Nighthawk bombers concentrated on striking the
shelters. These aircraft bombed from medium altitude before descending to verify the structure's destruction.
Meanwhile, coalition fighters patrolled the area to catch any Iraqi plane that managed to take off.

As you might imagine, the success of these airstrikes caused a panic among Iraqi forces who feared their entire
air force would be destroyed while still on the ground. Saddam Hussein was faced with a terrible dilemma--keep
his planes on the ground or commit them to combat and face almost certain destruction or have them flee to a
neutral nation. While coalition forces had expected Saddam Hussein to employ the latter tactic, it was
anticipated that the aircraft would flee west to Jordan, a nation friendly to the Iraqi regime, rather than to
long-time enemy Iran. In anticipation, coalition fighters routinely patrolled the skies over western Iraq to
catch any escape attempt. Again facing almost certain destruction, Hussein chose the only alternative left, that
of sending his planes east to Iran knowing that they would most likely survive and there was at least a chance
the aircraft would be returned at the end of the war.

And so it came as a great surprise to the coalition when, on 25 January 1991, American airborne early warning
aircraft observed a flight of seven aircraft flying towards the Iranian border. Whether this initial exodus was
planned or not was somewhat of a mystery as one of the planes disintegrated before crossing the border, two
announced technical malfunctions, and others reported a severe lack of fuel indicating that they were forced to
land in Iran due to distress. Iran immediately responded by declaring its neutrality in the war and denying that
any assistance had been offered to Iraq. Under the international laws of neutrality, Iran also promised to impound
the planes and their aircrews until the conclusion of the war. The Iraqi people learned of the news the next
day when the following announcement was aired on the Voice of the Iraqi Republic radio station:

"The spokesman of our army, the Iraqi Army, announces that several of our airplanes were forced to land in Iran
last night. Efforts are being made through regular channels to return the airplanes and their pilots to their
homeland."

Nonetheless, this first flight was only the beginning as Iraqi planes continued fleeing to Iran on a daily basis.
Though the US assigned F-15 interceptors to patrol the escape
routes (named Carol, Charlotte, Cindy, Eileen, and Emily) 24 hours a day, most Iraqi aircraft were able to evade
the patrols since the F-15s would not pursue them into Iranian airspace.

Over the course of several weeks, some 115 Iraqi warplanes were able to successfully escape to Iran. These
included

An additional 15 Ilyushin Il-76s, 17 civilian airliners,
and perhaps 2 Adnan I airborne early warning aircraft (based on the Russian
A-50) also fled to Iran.

Once the war had ended, Iraq of course attempted to recover its planes, but Iran was in no mood to return such
advanced war materiel to a nation it had fought a long and bloody war against just a few short years before.
Iran has claimed a staggering $1 trillion in reparations for damages suffered during that conflict, and has
thus far refused to return the aircraft until its demands are met. Even today, over ten years later, the planes
remain in Iran. As Saddam Hussein said in a speech on 8 August 2000,

"We erred in thinking that Iran was no longer an enemy of Iraq when we sent 115 of our aircraft there. Iran's
behavior is unprecedented. It refuses peaceful relations, in spite of all our peaceful initiatives."

So what has happened to all the Iraqi planes? While most remain stored in Iranian warehouses, a large number were
put back into service in the Iranian Air Force. In particular, the 24 Su-24s were formed into a new squadron,
repainted in Iranian markings, given new serial numbers, and even used to bomb Iraqi islands and border areas.
The 4 advanced MiG-29s were also absorbed into a squadron with 20 additional models purchased from Russia in the
early 1990s. While the 7 MiG-25s and 24 Mirage F.1s are also believed to be active, they are seldom used.
Meanwhile, the old and obsolete Su-20s, Su-22s, and MiG-23s were not worth the maintenance and training costs and
were placed in storage.

To address your final question, yes these Su-24s and MiG-29s certainly have improved the combat capability of the
Iranian Air Force. The Su-24s in particular significantly improved Iran's medium bomber force. Meanwhile, Iraq's
current air force is a mere shadow of what it once was. Following the Gulf War, these are the combat aircraft
that were estimated to remain: